Lock.



, J. 12 ERAS.

LOCK.

ION FILED APR. 9, 1910.

Patented Nov. 29, 1910.

ET I

AYPLIGAT W? 1 22655 es UNITED sT TEsrATENr onnion.

VINCENT J'OSEPHUS MARIE ERAS, 0F DGRDBECHT, NETHERLANDS.

LOCK.

To all whom it may concern: Be it known that I, VINCENT Josnrnus MARIE ERAS, a citizen of the Kingdom of the Netherlands, residing at Dordrecht, in the Kingdom of the Netherlands, have invented certain new and useful Improvements in Locks; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

In the case of the locks of the kind having a tumbler-catch cylinder, a revoluble cylinder is arranged in the lock casing which cylinder in its locked position is locked by resilient catches which penetrate laterally into the cylinder. On introducing a suitable key the catches are lifted to such an extent that their joints, or the places at which they are divided, coincide with the circumference of the revoluble cylinder, so that the latter can then be turned. These locks do not, however, ofier sufficient security against the possibility of being opened by unauthorized persons, since it is comparatively easy for a person at the outer side of the lock to bore away the catches in their lockin position particularly as the casing and also the catches consist of a material which does not rust and which is consequently soft. The lock can then be opened with any key, screwdriver, or the like.

Now the subject-matter of the application is a lock of the above-mentioned type inthe case of which it is practically impossible to borle away the catches and so unlock the loc The essence of the invention consists'in the feature that in the lock-casing and in front of the series of tumblers fixed screws or screw-pins are arranged, the points of which partially engage in an annular groove surrounding the revoluble cylinder and are so glass-hard that a boring tool cannot possibly enter at these places, but will be turned aside by the glass-hard screws and will be bent or will possibly break.

One embodiment of the present invention is illustrated, by way of example, in the accompanying drawing, in which:

Figure 1 is a section on the line A-A, Fig. 3 with an inserted key, Fig. 2 a sec tion on the line AA, Fig. 3 without a key but with a boring tool applied to the lock, and Fig. 3 a section on the line BB, 015 Fig. 1. p

The lock represented in the drawing os- Speciflcation of Letters Patent. Patented Nov. 29, 191%c Application filed April 9, 1910. Serial No. 554,556.

sesses in general the ordinary shap an n ipangement of the lock of the type in quesion.

1 is the cylinder, which is revolublein the lock-casing 2, and in the wall of which n the tumblers or catches 3 are guided, In

the example illustrated the catches are arranged in two diametrically, opposite rows, but of course the scope of the invention includes locks provided with only one row of tumblers. The tumblers are divided transversely into two parts which abut end to end and they are normally pressed by springs t to such a distance into the cylinder 1 that they prevent the latter from 1'0; tating. When a suitable key is introduced into the lock the tumblers are pressed outward, to such an extent that the places at which they are divided coincide with the circumference of the cylinder, so that the latter can be turned and the lock be unlocked by the operating member 5 connected with said cylinder.

screwed through the wall of the casing 2 in front of each row of tumblers radially with I so According to the invention a screw 6 is unlocking the look without authority, the

boring tool meets the glass-hard point of the screw and is turned aside by its convex sur-- face, so that the tool is bent or broken. After the lock has been secured on the object to be locked, the screws 6 are inaccessible and consequently they cannot be removed.

What I claim as my invention and desire to secure by Letters Patent is 1. A pin tumbler lock having a screw of hardened steel located within the cylinder in, advance of and completely protecting the pins and also provided with a plug recessed to receive the end of said screw.

2. A in tumbler lock havingia screw of hardene steel located within the cylinder and projecting into an annular groove in the plug, said screw being in advance of, and completely protecting the pins.

3. A pin tumbler lock havin screws of hardened steel located within t e cylinder and projecting into an annular groove in the plug at opposite points thereof, said screws being in advance of and completely protecting the pins.

4:. A pin tumbler look having a screw of hardened steel located within the cylinder in advance of and fully protecting the pins, said screw having a small integral end of hardened steel fitting into an annular groove in the plug and adapted to turn any boring instrument.

5. A pin tumbler lock having screws of hardened steel located in the cylinder, said screws having slightly decreased inwardly presented tips fitting into an annular groove in the plug, said pins being located in front of and completely protecting the pins.

6. A pin tumbler lock having a protecting part of hard metal located Within the cylinder and projecting at its inner end into an annular groove in the plug substantially as set forth.

7 A pin tumbler lock having protecting parts of hard metal located Within the cylinder and extending at their inner ends into an annular groove of the plug at opposite points thereof substantially as set forth.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing Witnesses.

VINCENT JOSEPHUS lliAltlE ERAS.

Witnesses:

ERNEST VoLLMER, L. Koo'r. 

